Some of Australia's top clothing labels are employing migrant workers for up to 15 hours a day in sweatshops while paying them as little as $5 an hour, according to court documents lodged by the textile union.

The union will argue that factories in the companies' supply chains are paying workers by the garment, which in some cases amounts to $5 to $6 an hour.

Advertisement

It says workers operate around the clock in sweatshops in factories, garages, sheds and retail shops across the country.

The union said the companies had been alerted to the problems.

A Vietnamese outworker, who spoke on the condition of anonymity, said she worked 10-hour days nearly every week, for the past 15 years. She earns a maximum of $13 an hour before tax and last took a holiday eight years ago.

She suffers back pain and high levels of stress, but continues to work from her living room, knowing she will lose her daily wage if she takes time to recover.

The managing director of Mariana Hardwick, Rebekah Hardwick, said she was ''shocked and saddened'' by the union's allegations, denying her label hired outworkers.

Two other clothing labels, Driza-Bone and Cubec, also deny the union's claims.